US8761999B2 - Level control system for a vehicle, and method for operating a level control system for a vehicle - Google Patents
Level control system for a vehicle, and method for operating a level control system for a vehicle Download PDFInfo
- Publication number
- US8761999B2 US8761999B2 US12/067,307 US6730706A US8761999B2 US 8761999 B2 US8761999 B2 US 8761999B2 US 6730706 A US6730706 A US 6730706A US 8761999 B2 US8761999 B2 US 8761999B2
- Authority
- US
- United States
- Prior art keywords
- vehicle body
- pressure
- body level
- prescribed
- soll
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related, expires
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
- B60G17/02—Spring characteristics, e.g. mechanical springs and mechanical adjusting means
- B60G17/04—Spring characteristics, e.g. mechanical springs and mechanical adjusting means fluid spring characteristics
- B60G17/052—Pneumatic spring characteristics
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
- B60G17/02—Spring characteristics, e.g. mechanical springs and mechanical adjusting means
- B60G17/04—Spring characteristics, e.g. mechanical springs and mechanical adjusting means fluid spring characteristics
- B60G17/052—Pneumatic spring characteristics
- B60G17/0523—Regulating distributors or valves for pneumatic springs
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
- B60G2400/25—Stroke; Height; Displacement
- B60G2400/252—Stroke; Height; Displacement vertical
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
- B60G2400/50—Pressure
- B60G2400/51—Pressure in suspension unit
- B60G2400/512—Pressure in suspension unit in spring
- B60G2400/5122—Fluid spring
- B60G2400/51222—Pneumatic
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G2500/00—Indexing codes relating to the regulated action or device
- B60G2500/20—Spring action or springs
- B60G2500/201—Air spring system type
- B60G2500/2014—Closed systems
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G2500/00—Indexing codes relating to the regulated action or device
- B60G2500/20—Spring action or springs
- B60G2500/205—Air-compressor operation
Definitions
- the invention relates to a level control system for a vehicle and to a method for operating a level control system for a vehicle, having a pressure generator for generating a pressure difference between a pressure medium reservoir and at least one pressure-controlled actuating device by means of which it is possible to set a prescribed vehicle body level, and having a valve device for carrying out an overflow process between the pressure medium reservoir and the at least one pressure-controlled actuating device.
- the level control system has at least one air spring that can be filled with compressed air in order to raise the vehicle body. If it is established on the basis of a pressure difference generated by using a compressor between a compressed air reservoir and the at least one air spring that the air pressure in the compressed air reservoir is greater than that in the at least one air spring, then in order to raise the vehicle body the at least one air spring is firstly connected to the compressed air reservoir by actuating a valve device in such a way that compressed air overflows from the compressed air reservoir into the at least one air spring. In this case, the air pressure in the air spring increasingly approximates to that in the compressed air reservoir.
- the pressure difference present between the compressed air reservoir and the at least one air spring reaches a prescribed threshold value that corresponds substantially to the production of a pressure equilibrium between the compressed air reservoir and the at least one air spring, and if it is established that there is a further need to fill the at least one air spring in order to raise the vehicle body to the desired level, this is performed by additional actuation of the compressor.
- the level control system for a vehicle further comprises a valve device for carrying out an overflow process between the pressure medium reservoir and the at least one pressure-controlled actuating device.
- an evaluation unit decides on the basis of a vehicle body level to be expected for the case of carrying out the overflow process whether and to what extent it is possible to set the prescribed vehicle body level solely by actuating the valve device.
- the pressure generator is typically an electrically driven compressor of current design. Since the compressor is actuated only when it is not possible, or only conditionally possible, to set the prescribed vehicle body level solely by actuating the valve device, the compressor run time as seen overall is reduced such that it is possible not only to prevent premature wear of the compressor, but also to substantially reduce the noise level in the region of the vehicle. The latter is of particular importance especially when the vehicle is stationary.
- the level control system serves, for example, for temporarily lowering the vehicle body in the case of higher driving speeds, in order to reduce the air resistance and thus the fuel consumption of the vehicle.
- the decision as to whether and to what extent it is possible to set the prescribed vehicle body level solely by actuating the valve device can be decided as a function of a comparison, which can be easily made by computer, between the prescribed vehicle body level and the vehicle body level to be expected for carrying out the overflow process.
- the safety reserve By suitably prescribing the safety reserve, it is possible to achieve indirectly that the vehicle body is raised or lowered, respectively, solely by actuating the valve device only when, as seen over the entire setting operation, there is an adequate pressure gradient between the pressure medium reservoir and the at least one pressure-controlled actuating device in order to ensure that the prescribed vehicle body level is rapidly achieved on the basis of carrying out the overflow process.
- the pressure generator is actuated in a supporting fashion—in order to speed up the setting operation.
- the pressure generator can be actuated here in a supporting fashion, in particular, with the expiry of the prescribed time period when, for example, it is established that, contrary to the original prediction or the original expectations, it has not yet been possible to achieve the prescribed vehicle body level solely by actuating the valve device.
- the vehicle body level to be expected can be calculated, in particular, on the basis of a pressure difference determined between the pressure medium reservoir and the at least one pressure-controlled actuating device. To this end, it is firstly estimated which pressure medium quantity may overflow between the pressure medium reservoir and the at least one pressure-controlled actuating device until a pressure equalization is produced. Finally, the vehicle body level to be expected at the at least one pressure-controlled actuating device is calculated from the pressure medium quantity thus estimated.
- the determination of the pressure difference can be performed here by using conventional pressure sensors.
- the at least one pressure-controlled actuating device is preferably a pneumatic or hydraulic spring leg of conventional design that is, in particular, a component of an active running gear of the vehicle.
- active running gears are present in any case with many vehicles, and so they are available for cost-efficient co-use.
- the device is advantageously a level control system having a closed pressure medium circuit, and so it is possible from the very start to exclude an escape into the surroundings of, in particular, compressed air loaded with contaminants (such as, for example, lubricant residues, wear-induced abrasion material and the like).
- contaminants such as, for example, lubricant residues, wear-induced abrasion material and the like.
- FIGURE shows a schematically illustrated exemplary embodiment of the inventive level control system.
- FIGURE shows a level control system according to the invention.
- a valve device 13 is present for carrying out an overflow process between the pressure medium reservoir 11 and the at least one pressure-controlled actuating device 12 i.
- the pressure generator 10 which is designed in the present case as an electrically actuatable compressor, permits pressure medium to be pumped to and fro in the closed pressure medium circuit of the level control system between the pressure medium reservoir 11 and the at least one pressure-controlled actuating device 12 i.
- the at least one pressure-controlled actuating device 12 i is, for example, a pneumatic or hydraulic spring leg that is arranged between a vehicle wheel and a support point assigned to the vehicle body in order to suppress undesired movements of the vehicle body caused by driving.
- the spring leg comprises, in essence, a pressure cylinder and a piston arranged therein in a fashion capable of displacement by pressure.
- a four-wheel vehicle is intended to be understood in this case, and so a total of four of the abovementioned actuating devices 12 a to 12 d are present, the actuating devices 12 a to 12 d being components of an active running gear of the vehicle.
- the valve device 13 comprises a separate electrically actuatable bypass valve 20 or 21 , respectively.
- a one-way valve 22 or 23 respectively, connected in series in each case, prevents an undesired backflow of pressure medium against the intended flow direction from being able to occur with an open bypass valve 20 or 21 .
- valve device 13 illustrated in the FIGURE is intended here merely by way of example.
- the valve device 13 can also alternatively have any desired other design that permits an overflow process from the pressure medium reservoir 11 in the direction of the at least one actuating device 12 i (and vice versa) to be carried out in a targeted way.
- actuating device 12 i and vice versa
- valve devices are present as required by principle, and so they are available from the very start for cost-efficient co-use in such a case.
- an evaluation unit 24 that decides on the basis of a vehicle body level d i,erw to be expected in the case of carrying out the overflow process whether and to what extent it is possible to set the prescribed vehicle body level d i,soll solely by actuating the valve device 13 , the latter being performed as a function of a comparison between the prescribed vehicle body level d i,soll and the vehicle body level d i,erw to be expected.
- the vehicle body level d i,soll to be set is prescribed, for example, by a control device (not illustrated) that is of a higher level than the level control system and is provided for temporarily lowering the vehicle body in the case of relatively high driving speeds, or in order to correct positional changes of the vehicle body caused by load changes.
- the sensing of the internal pressures p and p i is performed by means of a pressure sensing device 25 whose signals are fed to the evaluation unit 24 for determining the pressure difference ⁇ p.
- the pressure sensing device 25 has a number of pressure sensors (not illustrated) that are respectively assigned to the pressure medium reservoir 11 and to the actuating devices 12 i.
- the evaluation unit 24 Given from the determined pressure difference ⁇ p, the evaluation unit 24 considers the known internal volume V of the pressure medium reservoir 11 and the current internal volume V i , dependent on the respective piston position, of the actuating devices 12 i affected by the setting operation in order to estimate which pressure medium quantity ⁇ N max may overflow between the pressure medium reservoir 11 and the relevant actuating devices 12 i until a pressure equalization is produced.
- the current internal volume V i is derived in this case from the vehicle body level d i,ist instantaneously present at the actuating device 12 i ; the latter level permits a direct conclusion to be drawn in relation to the respective piston position of the actuating device 12 i.
- a level sensing device 26 is present whose signals are fed to the evaluation unit 24 .
- the level sensing device 26 has a number of actuator travel sensors (not illustrated) that are respectively assigned to the actuating devices 12 i.
- the evaluation unit 24 calculates a vehicle body level d i,soll to be expected for carrying out the overflow process, doing so from the pressure medium quantity ⁇ N max thus estimated, the current internal volume V i of the actuating device 12 i and its characteristic actuator response—in particular the change in the pressure-effective piston area of the actuating device 12 i as a function of the instantaneously present vehicle body level d i,ist .
- the evaluation unit 24 produces a pressure connection between the pressure medium reservoir 11 and the actuating devices 12 i affected by the setting operation, and this is performed by opening the bypass valve 21 and the shutoff valves 14 i of the relevant actuating devices 12 i .
- pressure medium flows from the pressure medium reservoir 11 into the respective actuating devices 12 i , the vehicle body thereby being raised in the region thereof.
- the pressure generator 10 is actuated in a supporting fashion.
- the supporting actuation of the pressure generator 10 is performed here with the expiry of the prescribed time period ⁇ t max when it is simultaneously established that, contrary to the original prediction or the original expectations, the prescribed vehicle body level d i,soll has not yet been achieved solely by actuating the valve device 13 . Whether the latter applies is detected by the evaluation unit 24 on the basis of a comparison of the instantaneously present vehicle body level d i,ist with the prescribed vehicle body level d i,soll .
- the vehicle body level d i,erw to be expected minus the safety reserve ⁇ d safe is smaller than the prescribed vehicle body level d i,soll , but is, per se, greater than or equal to the prescribed vehicle body level d i,soll , d i,erw ⁇ d safe ⁇ d i,soll ⁇ d i,erw , (2.2) it is concluded that a supporting actuation of the pressure generator 10 is required for setting the prescribed vehicle body level d i,soll in addition to carrying out the overflow process, said actuation being performed in the present case in such a way that pressure medium is pumped from the pressure medium reservoir 11 into the actuating devices 12 i affected by the setting operation.
- opening the bypass valve 21 is omitted and the setting operation is performed solely by actuating the pressure generator 10 .
- the vehicle body level d i,erw to be expected in the case of carrying out the overflow process directly from the internal pressures p, p i or the internal volumes V, V i .
- the calculation of the vehicle body level d i,erw to be expected can, in particular, also be performed on the basis of a dimensionless variable ⁇ i that represents the ratio between the current air mass m in the pressure medium reservoir 11 and the current air mass m i in the at least one actuating device 12 i ,
- the dimensionless variable ⁇ i thus obtained has the advantage that it is largely independent of the temperature. As a result, this enables a particularly simple and reliable calculation of the vehicle body level d i,erw respectively to be expected.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Vehicle Body Suspensions (AREA)
- Train Traffic Observation, Control, And Security (AREA)
- Steering Control In Accordance With Driving Conditions (AREA)
Abstract
Description
Δp=p−
in addition to the current internal pressure p of the
holds for this, in addition to the current internal pressure pi of the actuating device 12 i, a respectively associated weighting factor gi that assumes the
d i,erw −Δd safe ≧d i,soll. (2.1)
d i,erw −Δd safe <d i,soll ≦d i,erw, (2.2)
it is concluded that a supporting actuation of the
d i,erw <d i,soll (2.3)
it is impossible to set the prescribed vehicle body level di,soll on the basis of carrying out an overflow process.
is yielded from equation (2.4) in conjunction with the general gas equation p·V=m·R·T valid in this case, R representing the general gas constant (R=8 314 J/mol−1·K−1).
Claims (16)
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102005044806A DE102005044806A1 (en) | 2005-09-20 | 2005-09-20 | A level control system for a vehicle and method for operating a level control system for a vehicle |
DE102005044806.2 | 2005-09-20 | ||
DE102005044806 | 2005-09-20 | ||
PCT/EP2006/008556 WO2007033754A1 (en) | 2005-09-20 | 2006-09-01 | Level control system for a vehicle, and method for the operation thereof |
Publications (2)
Publication Number | Publication Date |
---|---|
US20080258413A1 US20080258413A1 (en) | 2008-10-23 |
US8761999B2 true US8761999B2 (en) | 2014-06-24 |
Family
ID=37188817
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/067,307 Expired - Fee Related US8761999B2 (en) | 2005-09-20 | 2006-09-01 | Level control system for a vehicle, and method for operating a level control system for a vehicle |
Country Status (7)
Country | Link |
---|---|
US (1) | US8761999B2 (en) |
EP (1) | EP1928676B1 (en) |
JP (1) | JP4864091B2 (en) |
KR (1) | KR101303210B1 (en) |
AT (1) | ATE450390T1 (en) |
DE (2) | DE102005044806A1 (en) |
WO (1) | WO2007033754A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11135888B2 (en) | 2019-02-26 | 2021-10-05 | Beijingwest Industries Co., Ltd. | Closed integrated air management module |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102008064647B4 (en) * | 2008-03-26 | 2011-09-22 | Miro Gudzulic | Measuring device for an air spring |
JP6201694B2 (en) | 2013-11-29 | 2017-09-27 | アイシン精機株式会社 | Vehicle height adjustment device |
DE102014218296A1 (en) * | 2014-09-12 | 2016-03-17 | Continental Teves Ag & Co. Ohg | Air suspension system with level control with selectable operating mode |
US10967697B2 (en) | 2016-03-29 | 2021-04-06 | Hitachi Automotive Systems, Ltd. | Air suspension system |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1004443A (en) | 1911-02-15 | 1911-09-26 | George B Miller | Chalk-line holder. |
US1017449A (en) | 1911-10-18 | 1912-02-13 | William C Neth | Metallic tie and rail-fastener. |
GB2344323A (en) | 1998-12-04 | 2000-06-07 | Rover Group | Pneumatic adjustable vehicle suspension |
US6266590B1 (en) | 1998-03-27 | 2001-07-24 | Daimlerchrysler Ag | Pneumatic suspension leveling system for vehicles |
DE10055108A1 (en) | 2000-11-07 | 2002-05-08 | Daimler Chrysler Ag | Pneumatic suspension for vehicle has induction side of pump connected via at least one valve to storage container or air springs |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3010967B2 (en) * | 1993-04-01 | 2000-02-21 | トヨタ自動車株式会社 | Air suspension control device |
JPH10914A (en) * | 1996-06-12 | 1998-01-06 | Toyota Motor Corp | Car height adjusting device |
KR19990059734A (en) * | 1997-12-31 | 1999-07-26 | 정몽규 | Car Air Suspension |
DE19959556C1 (en) * | 1999-12-10 | 2000-12-14 | Continental Ag | Closed loop level regulation device for automobile suspension has controlled switching valves coupling pump input and output to suspension springs or pressure reservoir dependent on air feed direction |
DE10006024C1 (en) * | 2000-02-11 | 2001-10-25 | Continental Ag | Method for filling pressure chambers of level regulator used in car suspension comprises feeding hydraulic fluid from reservoir to chambers while pressure difference exceeds threshold value and intermittently afterwards |
-
2005
- 2005-09-20 DE DE102005044806A patent/DE102005044806A1/en not_active Withdrawn
-
2006
- 2006-09-01 EP EP06791784A patent/EP1928676B1/en active Active
- 2006-09-01 WO PCT/EP2006/008556 patent/WO2007033754A1/en active Application Filing
- 2006-09-01 US US12/067,307 patent/US8761999B2/en not_active Expired - Fee Related
- 2006-09-01 JP JP2008530371A patent/JP4864091B2/en not_active Expired - Fee Related
- 2006-09-01 AT AT06791784T patent/ATE450390T1/en active
- 2006-09-01 KR KR1020087003502A patent/KR101303210B1/en active IP Right Grant
- 2006-09-01 DE DE502006005538T patent/DE502006005538D1/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1004443A (en) | 1911-02-15 | 1911-09-26 | George B Miller | Chalk-line holder. |
US1017449A (en) | 1911-10-18 | 1912-02-13 | William C Neth | Metallic tie and rail-fastener. |
US6266590B1 (en) | 1998-03-27 | 2001-07-24 | Daimlerchrysler Ag | Pneumatic suspension leveling system for vehicles |
GB2344323A (en) | 1998-12-04 | 2000-06-07 | Rover Group | Pneumatic adjustable vehicle suspension |
DE10055108A1 (en) | 2000-11-07 | 2002-05-08 | Daimler Chrysler Ag | Pneumatic suspension for vehicle has induction side of pump connected via at least one valve to storage container or air springs |
US6698778B2 (en) | 2000-11-07 | 2004-03-02 | Daimlerchrysler Ag | Air suspension having a closed compressed-air system |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11135888B2 (en) | 2019-02-26 | 2021-10-05 | Beijingwest Industries Co., Ltd. | Closed integrated air management module |
Also Published As
Publication number | Publication date |
---|---|
KR20080045679A (en) | 2008-05-23 |
WO2007033754A1 (en) | 2007-03-29 |
DE502006005538D1 (en) | 2010-01-14 |
JP4864091B2 (en) | 2012-01-25 |
EP1928676B1 (en) | 2009-12-02 |
ATE450390T1 (en) | 2009-12-15 |
EP1928676A1 (en) | 2008-06-11 |
JP2009513422A (en) | 2009-04-02 |
KR101303210B1 (en) | 2013-09-03 |
US20080258413A1 (en) | 2008-10-23 |
DE102005044806A1 (en) | 2007-03-29 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8761999B2 (en) | Level control system for a vehicle, and method for operating a level control system for a vehicle | |
US9328789B2 (en) | Vibration damping device for railway vehicle | |
JP4506687B2 (en) | Brake control device | |
US9511752B2 (en) | Method for operating a brake system, and brake system | |
JP4487956B2 (en) | Brake control device | |
RU2557641C1 (en) | Railway car damper | |
US7139649B2 (en) | Method for adaptation of a level of a vehicle with an air suspension element | |
KR20090083428A (en) | Proportional control valve | |
KR20210077073A (en) | Vehicle weight estivmating apparatus using height adjusting apparatus and method thereof | |
US9616871B2 (en) | Method of operating brake system | |
US20140196448A1 (en) | Hydraulic control apparatus and method | |
JP6069149B2 (en) | Brake control device | |
JP5268338B2 (en) | Actuator | |
CN101443204A (en) | Vehicle roll control system with self-centering actuator | |
EP3163115B1 (en) | Damper control device | |
US20170106840A1 (en) | Stopping control device for vehicle | |
JP2007145093A (en) | Vehicle height adjusting device | |
US11498384B2 (en) | Method and device for operating a pneumatic system with a compressed air supply unit and an air spring unit, pneumatic system comprising a compressed air supply unit and an air spring unit, and vehicle | |
US9315183B2 (en) | Brake pressure apply | |
JP2006298101A (en) | Vehicle height adjusting device | |
JP4525301B2 (en) | Brake device | |
JPH05254323A (en) | Suspension device | |
JP2009234397A (en) | Vehicle height adjustment device | |
JPH03178817A (en) | Car height adjustment device | |
KR20070094181A (en) | Vehicle electronic control suspension system and its operating method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: CONTINENTAL AKTIENGESELLSCHAFT, GERMANY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ILIAS, HEIKE;NETTELMANN, MARK;SPRENGEL, THOMAS;REEL/FRAME:020674/0146;SIGNING DATES FROM 20080110 TO 20080124 Owner name: CONTINENTAL AKTIENGESELLSCHAFT, GERMANY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ILIAS, HEIKE;NETTELMANN, MARK;SPRENGEL, THOMAS;SIGNING DATES FROM 20080110 TO 20080124;REEL/FRAME:020674/0146 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551) Year of fee payment: 4 |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20220624 |